PORTLAND, Maine — On Friday morning, while most city dwellers were still snoozing, a shipping container landed in Congress Square.

Instead of cargo en route to a distant port, the 20-by-8 storage unit was filled with arresting images of Maine.

From a dolled-up elderly street woman to a Lewiston hip-hop artist to a rural wintery landscape, the work of students at the Salt Institute for Documentary Studies has popped up in this urban park for a brief moment.

For the next six days, the industrial-box-turned-gallery on the edge of the park will showcase the art of storytelling that this school, a block away, represents.

The offshoot of Photoville NYC, a large-scale gathering of photography-filled freighter trucks that takes over the Brooklyn Bridge Park “Mad Max”-style in September, is designed to turn heads and spark conversation.

“People will just be walking by and see this pop-up container. It will pique people’s interest and they will say ‘Hey, what’s going on?” said Rachel Irwin, events and marketing manager for Portland’s Downtown District, a nonprofit group that promotes the city. “The main point is to bring something that’s sort of a surprise.”

For 40 years, the Salt Institute has been doing just that through radio essays, documentaries and photography that capture the essence of the state. The school holds monthly exhibits in a sleek modern space on Congress Street, but compared with larger arts organizations here, Salt is almost hidden in plain sight.

Photoville ME should change that.

“This is our chance to introduce ourselves to people,” said Donna Galluzzo, Salt’s executive director, “instead of waiting for people to come to us.”

The exhibit, which opens Saturday and runs through Thursday, includes video documentaries that will be projected onto a screen inside the shipping container and photo panels of students’ work.

Sam Barzilay, creative director for United Photo Industries who came up with the Photoville concept, is happy to see the Portland institute run with it.

“Our vision with containers is movement. We’d love to see them sprout across America,” he said from his offices in New York.

Photoville’s mission is the reverse gallery model.

“We are trying to put the work out on the street. We are trying to get it out of the white box so people will almost stumble upon them,” said Barzilay.

Photoville ME is the second extension of the concept. Barzilay launched one in a park in Sydney, Australia, earlier this summer.

Though there will only be one container here, compared with dozens in New York, Portland is considered a Photoville pioneer.

“I think there’s a bigger value to have them in smaller cities,” said Barzilay. “We are building the reputation for photography in areas that don’t have a wide audience.”

And in September, this container will be shipped up to New York to join the party.